1. Field of the Invention
The present invention relates to a drum washing machine which is capable of lifting clothes to a predetermined height and then dropping the lifted clothes so that the clothes can be washed by means of friction and impact, and more particularly to a steam jet drum washing machine which is capable of heating wash water and spraying the heated wash water into a tub and a drum of the washing machine in a phase of high-temperature and high-pressure steam, whereby sterilizing and washing efficiencies of the drum washing machine are improved.
2. Description of the Related Art
A drum washing machine is a kind of washer which is capable of washing clothes by friction between a drum rotated by a motor and the clothes put in the drum while a detergent and wash water are supplied in a horizontally mounted tub and the drum, which is disposed in the tub. With the drum washing machine, the clothes are neither damaged nor tangled with one another. Furthermore, the drum washing machine washes clothes by striking and rubbing the clothes, whereby washing efficiency is improved.
FIG. 1 is a perspective view of a conventional drum washing machine, and FIG. 2 is a side view, in cross section, of the conventional drum washing machine.
As shown in FIGS. 1 and 2, the conventional drum washing machine comprises: a casing 2 forming the exterior of the drum washing machine; a tub 6 disposed in the casing 2 in such a manner that the tub 6 is suspended by means of springs 4 and simultaneously supported by means of damper assemblies 5; a drum 8 rotatably mounted in the tub 6, in which clothes are put and into which wash water is supplied; a plurality of vanes 8a provided on the inner circumference of the drum 8 for lifting the clothes in the drum 8 as the drum 8 is rotated, the vanes 8a being longitudinally extended parallel to the axis of rotation of the drum 8 and inwardly protruded to a predetermined height while the vanes 8a are uniformly spaced apart from each other; and a motor 10 connected to the drum 8 in the rear of the tub 6 for rotating the drum 8.
The drum washing machine further comprises: a water-supply valve assembly 12 mounted above the tub 6 for supplying wash water into the tub 6 and the drum 8; a detergent box assembly 14 also mounted above the tub 6 for supplying a detergent into the tub 6 and the drum 8; and a drainage pump assembly 16 mounted below the tub 6 for draining the wash water from the tub 6 and the drum 8.
The drum 8 is provided at the inner circumference thereof with a plurality of through-holes 8h, through which the wash water flows between the drum 8 and the tub 6. When the drum 8 is rotated to dewater the clothes, the wash water contained in the clothes is separated from the clothes by means of the centrifugal force of the drum 8. At this time, the wash water separated from the clothes is discharged through the through-holes 8h. The water-supply valve assembly 12 includes a water-supply valve (not shown) so that the water-supply valve assembly 12 supplies wash water into the tub 6 and the drum 8 when the water-supply valve is opened. Similarly, the drainage pump assembly 16 includes a drainage pump (not shown) so that the drainage pump assembly 16 discharges the wash water from the tub 6 and the drum 8 when the drainage pump is operated.
To the lower part of the tub 6 is mounted a heater 20 for heating wash water in the tub 6 to a high temperature, by which the washing efficiency is improved. Specifically, the tub 6 includes a heater mounting part 6a formed at the lower part thereof. The heater mounting part 6a of the tub 6 is downwardly extended from the tub 6 so that the heater 20 is mounted in the heater mounting part 6a. The heater 20 is slidably inserted into the heater mounting part 6a of the tub 6 from the front part thereof, and then securely fixed to the heater mounting part 6a of the tub 6.
The operation of the conventional drum washing machine with the above-stated construction will now be described.
When a washing process is performed while clothes are put in the drum 8, the water-supply valve is opened so that a proper amount of wash water is supplied into the tub 6 and the drum 8 depending upon the amount of the clothes. The wash water passes through the water-supply valve assembly 12, and then passes through the detergent box assembly 14. The wash water having passed through the detergent box assembly 14 is supplied into the tub 6 together with a detergent.
When the drum 8 is rotated by operation of the motor 10, the clothes are lifted to a predetermined height by the vanes 8a and then dropped from the vanes 8a so that the clothes can be washed by means of friction and impact. At this time, the heater 20 may be operated to heat the wash water in the tub 6 so that the washing efficiency is improved.
After the washing process is finished, the drainage pump is operated so that the wash water is discharged. Subsequently, the motor 10 is rotated at a high speed, and thus the drum 8 is also rotated at a high speed. When the drum 8 is rotated, the wash water contained in the clothes is separated from the clothes by means of the centrifugal force of the drum 8. At this time, the wash water separated from the clothes is discharged through the through-holes 8h. In this way, an intermittent dewatering process is performed. Thereafter, the water-supply valve is opened again so that wash water is supplied into the tub 6 and the drum 8. At the same time, the drum 8 is rotated so that a rinsing process is performed.
The aforementioned rinsing and intermittent dewatering processes are alternately and repeatedly carried out, and finally a dewatering process is performed. In this way, a cleaning process comprising washing, rinsing, and dewatering processes is completed.
In the conventional drum washing machine, however, the wash water is supplied into the tub 6 from the upper part thereof together with the detergent via the water-supply valve assembly 12 and the detergent box assembly 14, and the wash water supplied into the tub 6 is heated by the heater 20 mounted to the lower part of the tub 6. As can be easily understood from the above description, the wash water initially supplied into the tub is cold. Consequently, the wash water is slowly absorbed by the clothes.
The conventional drum washing machine includes the heater mounting part 6a of the tub 6, which is provided so that the heater 20 is mounted in the tub 6. The heater mounting part 6a is formed at the lower part of the tub 6 in such a manner that the heater mounting part 6a is downwardly extended from the tub 6. Consequently, it is required to provide an additional space necessary for forming the heater mounting part 6a in the tub 6, which complicates construction of the drum washing machine.
The wash water supplied in the tub 6 is heated by the heater 20. Since the heater 20 is mounted in the heater mounting part 6a of the tub 6, the wash water is also filled in the heater mounting part 6a of the tub 6, and thus the wash water filled in the heater mounting part 6a of the tub 6 is also heated. However, the wash water filled in the heater mounting part 6a of the tub 6 is not used to wash the clothes. Consequently, wash water and electric energy are uselessly wasted. In addition, the detergent is left with the wash water in the heater mounting part 6a of the tub 6, by which the washing efficiency of the drum washing machine is decreased.